diff --git a/skeletons/per_decoder.c b/skeletons/per_decoder.c
index 16dee36..2e460da 100644
--- a/skeletons/per_decoder.c
+++ b/skeletons/per_decoder.c
@@ -30,6 +30,7 @@
 	}
 
 	/* Fill in the position indicator */
+	memset(&pd, 0, sizeof(pd));
 	pd.buffer = (const uint8_t *)buffer;
 	pd.nboff = skip_bits;
 	pd.nbits = 8 * size - unused_bits; /* 8 is CHAR_BIT from <limits.h> */